Brain image segmentation from ct data

• US 20100049035A1
• Filed: 08/25/2005
• Published: 02/25/2010
• Est. Priority Date: 05/27/2005
• Status: Abandoned Application

• Current Assignee: Agency For Science Technology and Research (Government of Singapore)
• Original Assignee: Agency For Science Technology and Research (Government of Singapore)
• Inventors: Qian, Guoyu, Aziz, Aamer, Nowinski, Wieslaw Lucjan, Hu, Qingmao
• Application Number:
  US11/921,122
• Publication Number:
  US 20100049035A1
• Time in Patent Office: Days
• US Class Current: 600/425
• CPC Class Codes: G06T 2207/10081 Computed x-ray tomography [CT]
• CPC Class Codes: G06T 2207/30016 Brain
• CPC Class Codes: G06T 7/11 Region-based segmentation
• CPC Class Codes: G06T 7/174 involving the use of two or more images
• CPC Class Codes: G06T 7/194 involving foreground-background segmentation

Abstract

The brain structure is extracted from CT data based on thresholding and brain mask propagation. Two thresholds are determined: a high threshold excludes the high intensity bones, while a low threshold excludes air and CSF. Brain mask propagation uses the spatial relevance of brain tissues in neighbouring slices to exclude non-brain tissues with similar intensities.

Claims

1. A method for generating a segmented brain image from a 2-dimensional slice computed tomography (CT) scan data set, comprising the steps of:

(a) choosing a reference slice of said CT data, and for said reference slice;

determining a region of interest;

determining a low threshold value from intensity values of said reference slice within said region of interest; and

determining a high threshold value from intensity values of said reference slice within said region of interest; and

(b) for each slice in said data set;

determining a region of interest;

performing a binarization of said slice components by use of said low threshold value and said high threshold value to give foreground connected components; and

excluding those foreground connected components that do not satisfy a spatial relevance criterion with reference to an adjacent slice.

2. A method according to claim 1, wherein said foreground connected components are those components having an intensity value falling between said low threshold value and said high threshold value.

3. A method according to claim 2, wherein said spatial relevance criterion is based on the number of foreground connected pixels in said slice being greater than a proportion of foreground connected pixels in said adjacent slice.

4. A method according to claim 3, wherein said excluding step includes determining brain candidate components from said foreground connected components by excluding those foreground connected components that are less than a predetermined distance from the skull defined as a brain mask boundary before applying said spatial relevance criterion.

5. A method according to claim 4, wherein said head mask boundary is determined with reference to . . . (p. 8)

11. Image data carried on a storage medium produced according to the method of claim 1.

12. Image data carried on a storage medium produced according to the method of claim 2.

13. Image data carried on a storage medium produced according to the method of claim 3.

14. Image data carried on a storage medium produced according to the method of claim 4.

15. Image data carried on a storage medium produced according to the method of claim 5.

6. Apparatus for generating a segmented brain image, comprising:

(a) a computed tomography (CT) scanner producing a CT scan data set;

(b) a processor;

generating 2-dimensional slice data from said data set;

for a reference slice of said CT data;

determining a region of interest, determining a low threshold value from intensity values of said reference slice within said region of interest, and determining a high threshold value from intensity values of said reference slice within said region of interest; and

for each slice in said data set;

determining a region of interest, performing a binarization of said slice components by use of said low threshold value and said high threshold value to give foreground connected components; and

excluding those foreground connected components that do not satisfy a spatial relevance criterion with reference to an adjacent slice; and

(c) a display device to display the non-excluded foreground connected components in each said slice as said segmented brain image.

7. Apparatus according to claim 6, wherein said processor determines said foreground connected components to be those components having an intensity value falling between said low threshold value and said high threshold value.

8. Apparatus according to claim 7, wherein said processor determines said spatial relevance criterion based on the number of foreground connected pixels in said slice being greater than a proportion of foreground connected pixels in said adjacent slice.

9. Apparatus according to claim 8, wherein said processor excludes brain candidate components from said foreground connected components by excluding those foreground connected components that are less than a predetermined distance from the skull defined as a brain mask boundary before applying said spatial relevance criterion.

10. Apparatus according to claim 9, wherein said head mask boundary is determined with reference to those foreground pixels within the neighbourhood of pixels where there is at least one background pixel.